SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7be0c2042372cd27d39975d7502e67294938df1f26290839ff4f495dbc3f164' 
  AND token = '140z/iD3DucEiBw/YJJ86Rd6NRe/c0a6rHzw30pDpB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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