SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab697530c17502e4473f97051520a3fad12aa7dfa06807fe290843236131ad43' 
  AND token = 'TtMp1idhM//4DVjL7jIC9LOBk4JtxZluYzCkpdWSwQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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