SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3c1cba889be6fdbb29fa0725d7c6dad57bcb667baefb1274b9dc1596fa633460' 
  AND token = 'LqJVkMJ1dCPKbfzK4ywvJzv0ihP+43xW9nporB7TAWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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