SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'af1a2743b073770b40496162baf03e234c2f5960374ad280ec36a8152bfa3d00' 
  AND token = 'AuUtKGFS8GdT5DphO0SbJITgOagOkrPbK4a8kz/NN20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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