SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a83ba99ab1b463ef15bfc55d6c052c89c1bc5770006b26a6acd71833240c3d7' 
  AND token = 'ESgi7G0Y95M8zXGNiubBMo8lb/qvUVZQItLoyPkLSKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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