SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '809e514ba16c2fbb99a7a3f12e325a17f6f48c2e871fcf06937f370a51784a38' 
  AND token = 'aehl1LQYhIFIcj2eUJ/JePiVFNSLI6kLVIqyGXnEkSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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