SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a853e52d2770739d486dd963a511582dae532a07108ea93458e1165ae58438cd' 
  AND token = '+UnRZY9Ded0pc/kSwYVRm93XEzA2XXUPZbibN5L22qc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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