SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7bc02710989f979022f4320f5180b6551487d3cb7f9dd36d8780174dfd5dc37' 
  AND token = 'rlYBxb+Yi50AEOKERPSPQxb+Nl0XioJX/dftyDLWaPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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