SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42a22c8dd89a7192b0f5293076d066001accef14a36addee8858be6cc00a4076' 
  AND token = 'fTeRI8I49Zk46RIRLafiiOqbCexexOVs9tBzJYEeOcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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