SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92f70149f71d266a4813ebbeeb2da1fc4ce675eaf1f730ffec352aafc1faecef' 
  AND token = 'x3+VA8qg2T75IHIvnrhSPe6QCkFUAxqjFmQwvv0LMoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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