SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b856e0e895eb3d1424fd097f7dfcda90435307a9bbb213e5d82e3e919ebce60e' 
  AND token = 'eCG++U3qYtFNPLhC1ffkRhlih5wVPVp3ZFEsHpYUJA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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