SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb776eee398c17e5d64cc484e92ab10d7332fec6f413ddda116ea1ee23b1fe2b' 
  AND token = 'm2D7Cvh2fJ5PzFolgKzE5PkokIdCnzc63MSMYD7dcVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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