SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c163f02a2d5d2a672d8972b393273f7675cf3205b2f967b5087780c917d706d' 
  AND token = 'hnDTrfXDL5hHurm5BoBZXnFIfCUPUOtQzAamgIAx99s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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