SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f21e104b0ccceb90102c9485de746a7b4b0482b08fc3843c2686c247f908a0b' 
  AND token = 'dA0m8oqcsatdfLqJJ3sRtwd7ubOEcMAVTOzkwZBAftE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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