SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba13ce5848f6426e515fb7be31f4ad972e64c69e20357be105317fe39743ea2e' 
  AND token = 'rQmBJB5ya7aTQpvxcsJg0bWqydKiNVVY2DusAiHU6I4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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