SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25dc2bfba363677cc8522a96437bbd4215dca93ea7c75d4c1326b59d964c3253' 
  AND token = 'nb4KONXtCRQj7cLcyt/Gq0ABpAGYyTAwAbDlyegfWeI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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