SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00f013acb2efbfc5d19f84c03918f6431324c3bbae53dd0ce77bc2d98add3b99' 
  AND token = 'mF8tPh0JLHiinKjqMpDdOKJPQuZsf5hgAWJKaubBB3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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