SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c88418089ff68cca091eef8de94b52165fe6824e2b13cc210d97077e5065e170' 
  AND token = 'MklbhFyBeVKQnm1YX+r0Xmw3RvYiv141i2IO8mJTtoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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