SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04563d4265cd7f46dff3aaf20f937d5c2b9cbf0c8221e7dfc8ad593afd9d6218' 
  AND token = 'R4wBUlzoIkKWTX3czbvb+rqL+N1LJPiBiLkrm4qmV58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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