SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ba7dcb95844e54e43859ff537d586a4f16544656063e3f429e8526494805ac1' 
  AND token = 'fA1zCDfAz3YDzcAOjMZckAe15w7DnWHAayK3ayriFo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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