SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd93d828ea65e57ac2e854a031e4a95e3a765dbe900b6ff2546f5ab2ebe773d8b' 
  AND token = 'HNF1xdoiASOzXc7u7+biDQJOeMKrqH6WDSzqea2p5Ko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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