SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3084bf9979883bf45a7ab9dfa55ac9418b427e215521dc13aca04752b1cdfa88' 
  AND token = 'ipjBZ2XYNKzLBfMEMU9mdOYY7PMESFMmfgy/rJvp1o8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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