SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e246cd142b5230746e84eb6a28fb06d1a0673c2a9b5ffa6751148aa52cf123ba' 
  AND token = 'X2Nx/MsSUhboeWqaQk1FJ7J7mdtwDQGJIaENMyZew6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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