SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d59ede3b6b9a275d3038879051bb6727b91982bd3ec7e803ccd1f729b7a90ed' 
  AND token = 'OqO93D8c+k1oTnWLSzOhZhxEY0NkwMpfsqVp+Gk7A18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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