Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9881d20b871dcd3413720bb0bc5ac292530c4febb3dd235eb86075fc46a62e2' 
  AND token = 'MO4eTF3TfxNtWGq3AZQKEX9pPtmfSt+YAUY8JZ7Eu1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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