SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e06b8579086366cd7996a783f9dc2dc93dca13cffc6ad77adb255fd0ddc20f52' 
  AND token = 'jIK30pSX/QLWKbvnHqBL0ktdVDvI/JjCy+1vzXfT+fQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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