SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56fd7cbbd4ab3a5356905ed010e1d37cf564180091a2804d8804643e8a1a7d08' 
  AND token = 'Sf4n4lkkfFvgZCc0HqZHbxsxT6ytCTPRv6qS7SS+pgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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