SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2616fc818c19a7cd8810aaf29742487edf4781f13fe0e029bf3a780efc21527c' 
  AND token = 'Lc/jOeU/Aknl65nYGpr9HNxTPqUzjQB2vK4LuNcOUew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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