SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dfe6adc8e87f5d2df5624eeb1f8466726de92b288916e6416c4d14a82a4c642' 
  AND token = 'M4kwwGs2JWmNisOgGRxNWBGlxv2oYete6n8qKSfukiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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