SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '66cb6fc56764f86f2be7974d08a986652b070007e168d8bf28a9d93d5372ce72' 
  AND token = 'obhdGBd/tN96rxjkWi6+eXNpdrN99LcZ3ZgW8Psutj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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