SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eea28261890a8d74628925285a7d4d90fbf6f2d018aabcec8b525774cb685d79' 
  AND token = 'q/2kKp0LeFerFwbah0y7xKckGmJBQESN1KBzoT2RFu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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