SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4cf571d30160c574773190dc2fc17e6acd1962e80b9e05e203317a5a958d2fb9' 
  AND token = 'fj3yUzp9kGV0DnUIJcHLKnY4u0dS1fVDz7qaS3RIg8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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