SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bbaa414f39a0cc8b76930799d02626dedb68af03a74defff953d84da12952d9' 
  AND token = 'bw20EKDhEAv2PXqTveO5WZYrB5TEZSNvNbPGAsuIZXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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