SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e8c28983ebe1db987da9f6c5cc50273e1a3f25d234e4b2d156ec151330a8779' 
  AND token = 'CBBg/ry8scxM8anUUI/zH4TwLfCG5vqNUEGl/jVb7G0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}