SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad2eb23b19cec6bc51afc0a6b7cbdcc9aca7ce12de8e3581a7a2d76aa6e44f6e' 
  AND token = 'efHF7MAKjnkTMol/LpEbfO9PssR5SIVX+BSWnStKIXI=' 
  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"
    }
  }
}