SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea9135d29cdf6e6a41751228885c59d4f986a8efa2d46eb92c358118b91a8784' 
  AND token = 'dz7We/aP1K/iu68JkbADfqhFKLboUQCciHiNZkQb7BU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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