SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2878474ab62c9da6d6963296312a86b3e5a1b4f6200721aa95d56b94617f51b7' 
  AND token = '0vdpO8GYKiBg47O4mSsNtZ1RfyhhMQJwXOEGeP1x48E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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