SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfb1bcb6f75d16462254f5a29e2eb796d1ddd6aaac07cdf32b713abdd8c802e2' 
  AND token = 'DDdJHY8ukWAQy32Z27K5oHnklL2GLtSqnc9gy4XTAEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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