SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f1802bbe06680a111096f96a2286133b02be3836dd70fe5bd09e006bc88ed20' 
  AND token = 'Fm5hrpeWxEaZsxHDsdlNEbX5kCZiA1RFfGHnH2tmLbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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