SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66a0360bd66a5367e37d920976eceb29b27d6e58a5c922e77a5fbcb0f4dc59fe' 
  AND token = 'zFbNchDoMOpIP0Qe9Y/LLERYvlC8JmrQUlKqet7NNS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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