SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9f6c49e9bff7cc187640e1fd80db975371f88274a6d2c5accfc3f5ce7c1db70' 
  AND token = '8ieW9s9WwYYs2Jm70vqOLkIRTfpguOEMIDdYWBddQWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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