SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2960d6e661cf9040a4eadf7853ec46b6d82eabdfe515a9f2664962ad4465ed94' 
  AND token = '2Ll/9svZMQxYHd0ZAarHrHGAP1xCcMuQDyxr4w2SA44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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