SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7adc3a79f3735fd78befce82a3048a2cee219eb00c15af8c09f57cc10b2ff81c' 
  AND token = 'gERiV0iIaFK8b85oVPfd3d/hkc4RdcoGz38O2eUgzbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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