SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c61b5fcf0032a9df869990dea2921bdd40305fbf1261c2eaa4fd29956d163054' 
  AND token = 'pGrHsUaKmHOupGJkgtcQLpIMXG7573KBRPuPtHtYMXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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