SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '610970b5d67868ef8802c8c38a80fd45a9aaf99731c254c307696b34729d88a1' 
  AND token = 'k/gWWg2MEIC78VISpl2v0tbK2YUoOxo69y0eJet6mzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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