SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b09bf94724f190f9df37a5a5fe06a1871319075634e496d75223017dea08f5b0' 
  AND token = 'KN6efxWgubT6frZBRokdiD6EG1DAKPvZu9ept4sWLio=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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