SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed5b9bf786f60ef3a59aaa995c48e45c9ff83ba9b371f349604b13683e0fdb5a' 
  AND token = 'o5Qs1k8RZDeA0PQR8RNf0QLtw0q1uj3DnSoYhJ9RNEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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