SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f6a13203f6ad27dd80f887c126164959f60ca3f8f287e1d3867d4231aae826f' 
  AND token = 'ZooaUAkBmff34TDUDWe1OBWBvRnycK/Ruqw+KNEpgaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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