SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd31f35373aa00e121184805d0a4f3074ec9f1253e1d90b106a2b607061f8385a' 
  AND token = 'TdhwAxqSlAWu8vLcUjJYH2pf3uISnxIE7P6m8n1u5c0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}