SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a891d346cd2aa7bd536310c0b522a2522cd832a402a720c402687abd05dc8ba0' 
  AND token = 'yfpyCLN8a+P03A6L+ruzq7+RwipHEKozGOl+htCLHlE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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