SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c89c4f585b817bbdf477a379a3604bdb541723217f05bb45ebe696aaaf67549f' 
  AND token = 'bzJwgq+ZkEq5mstuiC9+BCzjiZMuly1SNpPXdKB0CJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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