SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b95a143da51e94c68edaee1326400d8eabf2f093393b41f865afaeda1a92b906' 
  AND token = 'zU2XiOPaTEDiCw60S1V0HimJFqszKi/2pFXZ0dmEPPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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