SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99a0be9e26d21237faf2d860db2e8321e930a07be9174412ddfdcdb2166c0c56' 
  AND token = 'Xpv63f8BSNjD1uqchLEwiLaabLF1VlVO8EymmhaQlkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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