SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f733a8f69404eb266616534d26df645490cf7a9ede420bc0cd91a965dcbf288' 
  AND token = 'JTIB3gsh0LNEeV4ku7C+/iCG6zVOfWy/kJGH1JizXIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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