SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56adefd623a85acbb759be32bce8e11575cfa518cc0d0ed489e43b4f06681d3f' 
  AND token = 'gubcX6CSOnCHNUWYE8I2WWN58fZznNMLhKpS+0GArU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}