SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f85b18a523e9717568c7c2d022c896c6f1435921c4c595a14e10c3f7254c76c' 
  AND token = 'CMPPMukqzBJDD6ZuzV/2mYXrsKiZXS1R4kCu+GYlIU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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