SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d4e7bda8d5880b61baf7206162972d460d7fd57cdef41968015529f2201d56e' 
  AND token = 'qCFZwfaHyuOBZFsC/zjMTZhFrHp0Kh7uOAuT3pSc3ZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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