SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16218553054eb2a6d4973672b468e88eb04d37760293583022b791004e3ac788' 
  AND token = 'Shh9mZ3V8looHKPEpA/qhm2TMzSHBBkGpAk1v+Dxb+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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