SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e427252c902bd41ee72f8a3388d7c81191521fd9ac0611cdc5fa19e976d6a80e' 
  AND token = 'BrKGy2hva8c3hX1sYQAgb8wUFOb6mGzDTjyccZCsBRc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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