SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9c25d984ab6af39bb0e193ca3b102e1be1288f85bdd3ef7dcbdfb22952d51fa' 
  AND token = 'Aket2hXRRR+g0/9zEGIVQs/ovnFOCAJdIDXtwrvwJ44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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