SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '370d6e4018b5270341c6152da4cb83da36c5176af3d320f9418e76ce861aaca3' 
  AND token = 'j8SBRIGpQLpqf64XDW+io7msiZ3FWJEyiqOb9oxR2Nk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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