SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '89d3729c4c1f1f1dfc8874b64cec764a10597971e0af917d706df889d13e45be' 
  AND token = 'L+/PaSOn7AMDZLOcPKoq5M+tKcJVTDJiWEhKksem2zQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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