SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1c68a67b47cef9bf242d5200c9a7ae676b784385f485a5ab74e6061ee326768' 
  AND token = 'f023LMbIRTf+mpHG/FoqacWIn6NhOc/pYbLI/Hjt4b0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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