SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8843362236989ff39785647880fa8acc1c3d2157d20f7a2bea5a206bdb59e01c' 
  AND token = 'cUOULqnnfGCG071aBK0MRMAJugvFkAm3nXsq9Xu+Zgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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