SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a34827847f831f7faa705606f9f8914fd8a2aa553586c4e5cf2004f1f6c4c595' 
  AND token = 'gzfijgkhb0NwfT4jWtVX2XxN/TBXgzhdKN+hZViUavQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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