SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc8970977efe383144535fa89c3a131e80ea99dceb036f5bff1dfdb49203b614' 
  AND token = '2e6u/0yVB9WvHAz+iCS3KCAb6MJHfmin2rLEEoaFnyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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