SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08dafbb7f9575249bab6fc14c24a970b02d11dfe50f6edce74858605d8541f1c' 
  AND token = 'xCealbAUx1fp2lTGF0LKy39L+r+tgfEyJvDpit4N160=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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