SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83e42149f26913ccb063022058f519ab4c2d2ad798a71022a396300b6b3535e6' 
  AND token = '4JllPg25VBCRlrSs+8v5hZ4i7pRE3R0Wdyse8LQFRs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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