SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29528b1e7ceac26c01c4a5c1a642662be0a0437774de49005f6d7b5bf83f2556' 
  AND token = 'ZLgDzLLU7jMjg1KAkHRXAGA7ZN9Y90mX4iKCWB3kyVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}