SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f355118c2681e2248a9b8633d54b33b57eabf0f70aebabe377279ef45189334e' 
  AND token = 'wR14hvzpV96QaDhBZJb5Ke0EVH4UDn8ieGODUXGLp2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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